source/auth/token_util.c

   1 /*
   2  *  Unix SMB/CIFS implementation.
   3  *  Authentication utility functions
   4  *  Copyright (C) Andrew Tridgell 1992-1998
   5  *  Copyright (C) Andrew Bartlett 2001
   6  *  Copyright (C) Jeremy Allison 2000-2001
   7  *  Copyright (C) Rafal Szczesniak 2002
   8  *  Copyright (C) Volker Lendecke 2006
   9  *  Copyright (C) Michael Adam 2007
  10  *
  11  *  This program is free software; you can redistribute it and/or modify
  12  *  it under the terms of the GNU General Public License as published by
  13  *  the Free Software Foundation; either version 3 of the License, or
  14  *  (at your option) any later version.
  15  *
  16  *  This program is distributed in the hope that it will be useful,
  17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  *  GNU General Public License for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License
  22  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  23  */
  24
  25 /* functions moved from auth/auth_util.c to minimize linker deps */
  26
  27 #include "includes.h"
  28
  29 /****************************************************************************
  30  Check for a SID in an NT_USER_TOKEN
  31 ****************************************************************************/
  32
  33 bool nt_token_check_sid ( const DOM_SID *sid, const NT_USER_TOKEN *token )
  34 {
  35         int i;
  36
  37         if ( !sid || !token )
  38                 return False;
  39
  40         for ( i=0; i<token->num_sids; i++ ) {
  41                 if ( sid_equal( sid, &token->user_sids[i] ) )
  42                         return True;
  43         }
  44
  45         return False;
  46 }
  47
  48 bool nt_token_check_domain_rid( NT_USER_TOKEN *token, uint32 rid )
  49 {
  50         DOM_SID domain_sid;
  51
  52         /* if we are a domain member, the get the domain SID, else for
  53            a DC or standalone server, use our own SID */
  54
  55         if ( lp_server_role() == ROLE_DOMAIN_MEMBER ) {
  56                 if ( !secrets_fetch_domain_sid( lp_workgroup(),
  57                                                 &domain_sid ) ) {
  58                         DEBUG(1,("nt_token_check_domain_rid: Cannot lookup "
  59                                  "SID for domain [%s]\n", lp_workgroup()));
  60                         return False;
  61                 }
  62         }
  63         else
  64                 sid_copy( &domain_sid, get_global_sam_sid() );
  65
  66         sid_append_rid( &domain_sid, rid );
  67
  68         return nt_token_check_sid( &domain_sid, token );\
  69 }
  70
  71 /******************************************************************************
  72  Create a token for the root user to be used internally by smbd.
  73  This is similar to running under the context of the LOCAL_SYSTEM account
  74  in Windows.  This is a read-only token.  Do not modify it or free() it.
  75  Create a copy if your need to change it.
  76 ******************************************************************************/
  77
  78 NT_USER_TOKEN *get_root_nt_token( void )
  79 {
  80         struct nt_user_token *token, *for_cache;
  81         DOM_SID u_sid, g_sid;
  82         struct passwd *pw;
  83         void *cache_data;
  84
  85         cache_data = memcache_lookup_talloc(
  86                 NULL, SINGLETON_CACHE_TALLOC,
  87                 data_blob_string_const("root_nt_token"));
  88
  89         if (cache_data != NULL) {
  90                 return talloc_get_type_abort(
  91                         cache_data, struct nt_user_token);
  92         }
  93
  94         if ( !(pw = sys_getpwnam( "root" )) ) {
  95                 DEBUG(0,("get_root_nt_token: getpwnam(\"root\") failed!\n"));
  96                 return NULL;
  97         }
  98
  99         /* get the user and primary group SIDs; although the
 100            BUILTIN\Administrators SId is really the one that matters here */
 101
 102         uid_to_sid(&u_sid, pw->pw_uid);
 103         gid_to_sid(&g_sid, pw->pw_gid);
 104
 105         token = create_local_nt_token(NULL, &u_sid, False,
 106                                       1, &global_sid_Builtin_Administrators);
 107
 108         token->privileges = se_disk_operators;
 109
 110         for_cache = token;
 111
 112         memcache_add_talloc(
 113                 NULL, SINGLETON_CACHE_TALLOC,
 114                 data_blob_string_const("root_nt_token"), &for_cache);
 115
 116         return token;
 117 }
 118
 119
 120 /*
 121  * Add alias SIDs from memberships within the partially created token SID list
 122  */
 123
 124 NTSTATUS add_aliases(const DOM_SID *domain_sid,
 125                      struct nt_user_token *token)
 126 {
 127         uint32 *aliases;
 128         size_t i, num_aliases;
 129         NTSTATUS status;
 130         TALLOC_CTX *tmp_ctx;
 131
 132         if (!(tmp_ctx = talloc_init("add_aliases"))) {
 133                 return NT_STATUS_NO_MEMORY;
 134         }
 135
 136         aliases = NULL;
 137         num_aliases = 0;
 138
 139         status = pdb_enum_alias_memberships(tmp_ctx, domain_sid,
 140                                             token->user_sids,
 141                                             token->num_sids,
 142                                             &aliases, &num_aliases);
 143
 144         if (!NT_STATUS_IS_OK(status)) {
 145                 DEBUG(10, ("pdb_enum_alias_memberships failed: %s\n",
 146                            nt_errstr(status)));
 147                 goto done;
 148         }
 149
 150         for (i=0; i<num_aliases; i++) {
 151                 DOM_SID alias_sid;
 152                 sid_compose(&alias_sid, domain_sid, aliases[i]);
 153                 status = add_sid_to_array_unique(token, &alias_sid,
 154                                                  &token->user_sids,
 155                                                  &token->num_sids);
 156                 if (!NT_STATUS_IS_OK(status)) {
 157                         DEBUG(0, ("add_sid_to_array failed\n"));
 158                         goto done;
 159                 }
 160         }
 161
 162 done:
 163         TALLOC_FREE(tmp_ctx);
 164         return NT_STATUS_OK;
 165 }
 166
 167 /*******************************************************************
 168 *******************************************************************/
 169
 170 static NTSTATUS add_builtin_administrators( struct nt_user_token *token )
 171 {
 172         DOM_SID domadm;
 173         NTSTATUS status;
 174
 175         /* nothing to do if we aren't in a domain */
 176
 177         if ( !(IS_DC || lp_server_role()==ROLE_DOMAIN_MEMBER) ) {
 178                 return NT_STATUS_OK;
 179         }
 180
 181         /* Find the Domain Admins SID */
 182
 183         if ( IS_DC ) {
 184                 sid_copy( &domadm, get_global_sam_sid() );
 185         } else {
 186                 if ( !secrets_fetch_domain_sid( lp_workgroup(), &domadm ) )
 187                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 188         }
 189         sid_append_rid( &domadm, DOMAIN_GROUP_RID_ADMINS );
 190
 191         /* Add Administrators if the user beloongs to Domain Admins */
 192
 193         if ( nt_token_check_sid( &domadm, token ) ) {
 194                 status = add_sid_to_array(token,
 195                                           &global_sid_Builtin_Administrators,
 196                                           &token->user_sids, &token->num_sids);
 197         if (!NT_STATUS_IS_OK(status)) {
 198                         return status;
 199                 }
 200         }
 201
 202         return NT_STATUS_OK;
 203 }
 204
 205 /*******************************************************************
 206 *******************************************************************/
 207
 208 static NTSTATUS create_builtin_users( void )
 209 {
 210         NTSTATUS status;
 211         DOM_SID dom_users;
 212
 213         status = pdb_create_builtin_alias( BUILTIN_ALIAS_RID_USERS );
 214         if ( !NT_STATUS_IS_OK(status) ) {
 215                 DEBUG(5,("create_builtin_users: Failed to create Users\n"));
 216                 return status;
 217         }
 218
 219         /* add domain users */
 220         if ((IS_DC || (lp_server_role() == ROLE_DOMAIN_MEMBER))
 221                 && secrets_fetch_domain_sid(lp_workgroup(), &dom_users))
 222         {
 223                 sid_append_rid(&dom_users, DOMAIN_GROUP_RID_USERS );
 224                 status = pdb_add_aliasmem( &global_sid_Builtin_Users, &dom_users);
 225                 if ( !NT_STATUS_IS_OK(status) ) {
 226                         DEBUG(4,("create_builtin_administrators: Failed to add Domain Users to"
 227                                 " Users\n"));
 228                         return status;
 229                 }
 230         }
 231
 232         return NT_STATUS_OK;
 233 }
 234
 235 /*******************************************************************
 236 *******************************************************************/
 237
 238 static NTSTATUS create_builtin_administrators( void )
 239 {
 240         NTSTATUS status;
 241         DOM_SID dom_admins, root_sid;
 242         fstring root_name;
 243         enum lsa_SidType type;
 244         TALLOC_CTX *ctx;
 245         bool ret;
 246
 247         status = pdb_create_builtin_alias( BUILTIN_ALIAS_RID_ADMINS );
 248         if ( !NT_STATUS_IS_OK(status) ) {
 249                 DEBUG(5,("create_builtin_administrators: Failed to create Administrators\n"));
 250                 return status;
 251         }
 252
 253         /* add domain admins */
 254         if ((IS_DC || (lp_server_role() == ROLE_DOMAIN_MEMBER))
 255                 && secrets_fetch_domain_sid(lp_workgroup(), &dom_admins))
 256         {
 257                 sid_append_rid(&dom_admins, DOMAIN_GROUP_RID_ADMINS);
 258                 status = pdb_add_aliasmem( &global_sid_Builtin_Administrators, &dom_admins );
 259                 if ( !NT_STATUS_IS_OK(status) ) {
 260                         DEBUG(4,("create_builtin_administrators: Failed to add Domain Admins"
 261                                 " Administrators\n"));
 262                         return status;
 263                 }
 264         }
 265
 266         /* add root */
 267         if ( (ctx = talloc_init("create_builtin_administrators")) == NULL ) {
 268                 return NT_STATUS_NO_MEMORY;
 269         }
 270         fstr_sprintf( root_name, "%s\\root", get_global_sam_name() );
 271         ret = lookup_name(ctx, root_name, LOOKUP_NAME_DOMAIN, NULL, NULL,
 272                           &root_sid, &type);
 273         TALLOC_FREE( ctx );
 274
 275         if ( ret ) {
 276                 status = pdb_add_aliasmem( &global_sid_Builtin_Administrators, &root_sid );
 277                 if ( !NT_STATUS_IS_OK(status) ) {
 278                         DEBUG(4,("create_builtin_administrators: Failed to add root"
 279                                 " Administrators\n"));
 280                         return status;
 281                 }
 282         }
 283
 284         return NT_STATUS_OK;
 285 }
 286
 287
 288 /*******************************************************************
 289  Create a NT token for the user, expanding local aliases
 290 *******************************************************************/
 291
 292 struct nt_user_token *create_local_nt_token(TALLOC_CTX *mem_ctx,
 293                                             const DOM_SID *user_sid,
 294                                             bool is_guest,
 295                                             int num_groupsids,
 296                                             const DOM_SID *groupsids)
 297 {
 298         struct nt_user_token *result = NULL;
 299         int i;
 300         NTSTATUS status;
 301         gid_t gid;
 302
 303         DEBUG(10, ("Create local NT token for %s\n",
 304                    sid_string_dbg(user_sid)));
 305
 306         if (!(result = TALLOC_ZERO_P(mem_ctx, struct nt_user_token))) {
 307                 DEBUG(0, ("talloc failed\n"));
 308                 return NULL;
 309         }
 310
 311         /* Add the user and primary group sid */
 312
 313         status = add_sid_to_array(result, user_sid,
 314                                   &result->user_sids, &result->num_sids);
 315         if (!NT_STATUS_IS_OK(status)) {
 316                 return NULL;
 317         }
 318
 319         /* For guest, num_groupsids may be zero. */
 320         if (num_groupsids) {
 321                 status = add_sid_to_array(result, &groupsids[0],
 322                                           &result->user_sids,
 323                                           &result->num_sids);
 324                 if (!NT_STATUS_IS_OK(status)) {
 325                         return NULL;
 326                 }
 327         }
 328
 329         /* Add in BUILTIN sids */
 330
 331         status = add_sid_to_array(result, &global_sid_World,
 332                                   &result->user_sids, &result->num_sids);
 333         if (!NT_STATUS_IS_OK(status)) {
 334                 return NULL;
 335         }
 336         status = add_sid_to_array(result, &global_sid_Network,
 337                                   &result->user_sids, &result->num_sids);
 338         if (!NT_STATUS_IS_OK(status)) {
 339                 return NULL;
 340         }
 341
 342         if (is_guest) {
 343                 status = add_sid_to_array(result, &global_sid_Builtin_Guests,
 344                                           &result->user_sids,
 345                                           &result->num_sids);
 346                 if (!NT_STATUS_IS_OK(status)) {
 347                         return NULL;
 348                 }
 349         } else {
 350                 status = add_sid_to_array(result,
 351                                           &global_sid_Authenticated_Users,
 352                                           &result->user_sids,
 353                                           &result->num_sids);
 354                 if (!NT_STATUS_IS_OK(status)) {
 355                         return NULL;
 356                 }
 357         }
 358
 359         /* Now the SIDs we got from authentication. These are the ones from
 360          * the info3 struct or from the pdb_enum_group_memberships, depending
 361          * on who authenticated the user.
 362          * Note that we start the for loop at "1" here, we already added the
 363          * first group sid as primary above. */
 364
 365         for (i=1; i<num_groupsids; i++) {
 366                 status = add_sid_to_array_unique(result, &groupsids[i],
 367                                                  &result->user_sids,
 368                                                  &result->num_sids);
 369                 if (!NT_STATUS_IS_OK(status)) {
 370                         return NULL;
 371                 }
 372         }
 373
 374         /* Deal with the BUILTIN\Administrators group.  If the SID can
 375            be resolved then assume that the add_aliasmem( S-1-5-32 )
 376            handled it. */
 377
 378         if ( !sid_to_gid( &global_sid_Builtin_Administrators, &gid ) ) {
 379                 /* We can only create a mapping if winbind is running
 380                    and the nested group functionality has been enabled */
 381
 382                 if ( lp_winbind_nested_groups() && winbind_ping() ) {
 383                         become_root();
 384                         status = create_builtin_administrators( );
 385                         if ( !NT_STATUS_IS_OK(status) ) {
 386                                 DEBUG(2,("WARNING: Failed to create BUILTIN\\Administrators "
 387                                          "group!  Can Winbind allocate gids?\n"));
 388                                 /* don't fail, just log the message */
 389                         }
 390                         unbecome_root();
 391                 }
 392                 else {
 393                         status = add_builtin_administrators( result );
 394                         if ( !NT_STATUS_IS_OK(status) ) {
 395                                 /* just log a complaint but do not fail */
 396                                 DEBUG(3,("create_local_nt_token: failed to check for local Administrators"
 397                                         " membership (%s)\n", nt_errstr(status)));
 398                         }
 399                 }
 400         }
 401
 402         /* Deal with the BUILTIN\Users group.  If the SID can
 403            be resolved then assume that the add_aliasmem( S-1-5-32 )
 404            handled it. */
 405
 406         if ( !sid_to_gid( &global_sid_Builtin_Users, &gid ) ) {
 407                 /* We can only create a mapping if winbind is running
 408                    and the nested group functionality has been enabled */
 409
 410                 if ( lp_winbind_nested_groups() && winbind_ping() ) {
 411                         become_root();
 412                         status = create_builtin_users( );
 413                         if ( !NT_STATUS_IS_OK(status) ) {
 414                                 DEBUG(2,("WARNING: Failed to create BUILTIN\\Users group! "
 415                                          "Can Winbind allocate gids?\n"));
 416                                 /* don't fail, just log the message */
 417                         }
 418                         unbecome_root();
 419                 }
 420         }
 421
 422         /* Deal with local groups */
 423
 424         if (lp_winbind_nested_groups()) {
 425
 426                 become_root();
 427
 428                 /* Now add the aliases. First the one from our local SAM */
 429
 430                 status = add_aliases(get_global_sam_sid(), result);
 431
 432                 if (!NT_STATUS_IS_OK(status)) {
 433                         unbecome_root();
 434                         TALLOC_FREE(result);
 435                         return NULL;
 436                 }
 437
 438                 /* Finally the builtin ones */
 439
 440                 status = add_aliases(&global_sid_Builtin, result);
 441
 442                 if (!NT_STATUS_IS_OK(status)) {
 443                         unbecome_root();
 444                         TALLOC_FREE(result);
 445                         return NULL;
 446                 }
 447
 448                 unbecome_root();
 449         }
 450
 451
 452         get_privileges_for_sids(&result->privileges, result->user_sids,
 453                                 result->num_sids);
 454         return result;
 455 }
 456
 457 /****************************************************************************
 458  prints a NT_USER_TOKEN to debug output.
 459 ****************************************************************************/
 460
 461 void debug_nt_user_token(int dbg_class, int dbg_lev, NT_USER_TOKEN *token)
 462 {
 463         size_t     i;
 464
 465         if (!token) {
 466                 DEBUGC(dbg_class, dbg_lev, ("NT user token: (NULL)\n"));
 467                 return;
 468         }
 469
 470         DEBUGC(dbg_class, dbg_lev,
 471                ("NT user token of user %s\n",
 472                 sid_string_dbg(&token->user_sids[0]) ));
 473         DEBUGADDC(dbg_class, dbg_lev,
 474                   ("contains %lu SIDs\n", (unsigned long)token->num_sids));
 475         for (i = 0; i < token->num_sids; i++)
 476                 DEBUGADDC(dbg_class, dbg_lev,
 477                           ("SID[%3lu]: %s\n", (unsigned long)i,
 478                            sid_string_dbg(&token->user_sids[i])));
 479
 480         dump_se_priv( dbg_class, dbg_lev, &token->privileges );
 481 }
 482
 483 /****************************************************************************
 484  prints a UNIX 'token' to debug output.
 485 ****************************************************************************/
 486
 487 void debug_unix_user_token(int dbg_class, int dbg_lev, uid_t uid, gid_t gid,
 488                            int n_groups, gid_t *groups)
 489 {
 490         int     i;
 491         DEBUGC(dbg_class, dbg_lev,
 492                ("UNIX token of user %ld\n", (long int)uid));
 493
 494         DEBUGADDC(dbg_class, dbg_lev,
 495                   ("Primary group is %ld and contains %i supplementary "
 496                    "groups\n", (long int)gid, n_groups));
 497         for (i = 0; i < n_groups; i++)
 498                 DEBUGADDC(dbg_class, dbg_lev, ("Group[%3i]: %ld\n", i,
 499                         (long int)groups[i]));
 500 }
 501
 502 /* END */